The inventor is aware of the use of high explosives to blast break rock to tunnel into rock. Although this is a well-established method for forming tunnels in rock, it suffers from a number of disadvantages and limitations.
Traditional explosives atomise, the rock and ore, in an area with an approximate diameter of up to 100 mm, around and in the vicinity of the drilled hole, from the explosives, including ore such as gold, and create large volumes of toxic dust. Ore from the dust is lost and the dust needs to be managed, at great cost, for safety reasons. Using high explosives requires (in some cases) the entire mine to be evacuated or partly evacuated, leading to down time. Due to the shock waves caused by high explosives other parts of the mine may be caved in or destabilized contributing to the danger of an already a hazardous working environment. In addition, the highly concentrated ore reefs or veins are blown up together with rock, which dilute the ore extensively. Tunnelling methods using traditional explosives can, for obvious reasons, not be continuous.
The inventor is also the inventor of a tunnelling method, which use a propellant base cartridge, rather than an explosive. This method includes the steps of drilling a series of interfering parallel holes or a pilot hole into and generally perpendicular into a rock face, drilling a first series of blasting holes around the pilot hole, loading the first series of holes with propellant charges, igniting the charges, and repeating the process for further series of blasting holes until the diameter of the tunnel is reached. The inventor believes that this method lends itself to automation and a machine for continuous tunnelling at high speeds.
It is an object of the invention to provide a machine for tunnelling in rock, which is, semi-or fully automated, continuous, fast and safer and more controlled than traditional tunnelling methods and which does not suffer from the disadvantages of using high explosives.